Recognition of the unique structure of DNA:RNA hybrids

Targeting nucleic acids using small molecules routinely uses the end products in the conversion pathway of "DNA to RNA, RNA to protein". However, the intermediate processes in this path have not always been targeted. The DNA-RNA interaction, specifically DNA:RNA hybrid formation, provides a unique target for controlling the transfer of genetic information through binding by small molecules. Not only do DNA:RNA hybrids differ in conformation from widely targeted DNA and RNA, the low occurrence within biological systems further validates their therapeutic potential. Surprisingly, a survey of the literature reveals only a handful of ligands that bind DNA:RNA hybrids; in comparison, the number of ligands designed to target DNA is in the thousands. DNA:RNA hybrids, from their scientific inception to current applications in ligand targeting, are discussed.